Presently known magnetoresistive (MR) heads include a write element for recording signals and a magnetoresistive (MR) sensor for reading the recorded signals. Compared to previous designs, current MR heads are up to 100 times more susceptible to damage during manufacture caused by electrostatic discharge (ESD). During manufacture, the drive elements including the MR head are open to the environment and subject to possible ESD from human handling. In contrast, during operation of the drive in a computer, the elements are encased in a protective cover with appropriate protections against ESD.
One prior approach to protection from ESD damage is described in U.S. Pat. No. 6,034,851 entitled “Shorting bar and test clip for protecting magnetic heads from damage caused by electrostatic discharge during manufacture.” Such patent discloses a method and apparatus for selectively disabling a magnetic head to protect the head from damage caused by ESD during manufacture. The magnetic head is electrically attached to a flexure. The flexure has a set of test pads and a hinged portion that includes a shorting bar. The hinged portion of the flexure is folded to cause the shorting bar to short the test pads. The folded portion is secured with a clip which may be removed and replaced. A novel test clip is used with the flexure. The folded flexure is inserted into jaws of the test clip. The jaws clamp the folded flexure. The shorting bar shorts the sensor when the test clip is in a first position and removes the short when the test clip is moved to a second position.
Another prior approach to protection from ESD damage is described in U.S. Pat. No. 6,351,352 entitled “Separably bondable shunt for wireless suspensions.” Such invention provides continuing shunt protection of wireless suspension assemblies with a shunt structure that is readily attached to and detached from the contact pads or other exposed areas of the conductive traces of the flexible conductive laminate portion of the wireless suspension for use as needed to protect the MR and GMR elements/heads. The shunt structure comprises a conductive web to connect the conductive traces in parallel, and adhesive allowing the separable attachment of the web to the traces. The metal or metal deposited conductive web has varying geometries of conductive areas and adhesive areas to allow conductive web attachment to the proximate contact pads of the suspension, to be removed during testing and left on during assembly and between tests to nearly continually protect the head magnetoresistive element, or, to provide continuous ESD protection for the MR and GMR element attached to a flexible conductive circuit, to allow conductive web attachment to the traces beyond the contact pads such that the web is left in place during suspension assembly, during testing and between tests.
Unfortunately, it is impractical or impossible to reuse the foregoing ESD-prevention designs. For example, the first design is integrally coupled to the MR connection cable, while the second design uses adhesive which may loose effectiveness. There is thus a need for an ESD-prevention design which may be re-used, as well as provide more effective protection from ESD damage in particular environments such as in use with a tape drive compression connector cable, for example.